The Republican nominating contest for president could be consolidating into a two-man race between businessman Donald Trump and Texas Senator Ted Cruz. By gobbling up the lion’s share of delegates awarded state-by-state, Trump and Cruz are eclipsing two other rivals: Florida Senator Marco Rubio and Ohio governor John Kasich.

Rubio did pick up a victory Sunday in Puerto Rico's primary, only his second win of the 2016 cycle. For now he appears to pose no threat to Cruz or Trump.

Cruz beat expectations by winning nominating contests Saturday in Maine and Kansas, and finishing a close second to front-runner Donald Trump in Louisiana and Kentucky.

“I am very encouraged because if we continue to unite we are going to win this nomination,” said a jubilant Cruz.

“I am very, very happy about it. Thank you Louisiana and thank you Kentucky,” he said.

While Trump retains a lead in the delegates needed to win the Republican nomination, Cruz narrowed the gap by winning five states last week.

Squabble with Rubio

On Thursday, Trump and Rubio squabbled endlessly at the last Republican debate, often eliciting groans and boos from the audience. Cruz alternated between attacking Trump and attempting to stand above the fray.

“Nominating Donald would be a disaster,” Cruz said at the debate, which was televised on Fox News. “If you don’t want him as the nominee, then I ask you to stand with us as a broad coalition of people who believe in the Constitution, believe in freedom, and want to turn this country around.”

Trump acknowledged Cruz's rise late Saturday and urged Rubio to drop out of the race.

A woman marks her vote for Florida's Senator Marco Rubio during Puerto Rico's Republican primary in San Juan, Puerto Rico, March 6, 2016.

"I would love to take on Ted one-on-one. That would be so much fun," he said.

If Cruz is emerging as the main alternative to Trump among Republicans, the Democratic front-runner, former Secretary of State Hillary Clinton, continued marching toward her party's nomination.

Her lone challenger, Vermont Senator Bernie Sanders, won the caucuses Sunday in Maine.

But that will have little effect on Clinton increasingly gearing her remarks to a general election audience.

“Let us join hands, let us lift ourselves up, let us get going together. Let us make a difference, let us build tomorrow,” Clinton said at a recent campaign stop.

Delegate race

Clinton has won most primaries to date in larger, delegate-rich states. But Bernie Sanders insists the race is not over.

“We have come a very, very long way, closing the gap nationally with Secretary Clinton,” Sanders said on ABC’s This Week television program.

But it is the Republican contest that is generating more headlines. Some party elders, like 2012 Republican presidential nominee Mitt Romney, have pleaded with voters against backing Trump.

“Here is what I know. Donald Trump is a phony, a fraud,” Romney said last week.

FILE - Former Secretary of State Hillary Clinton talks as Sen. Bernie Sanders of Vermont listens during the CNN Democratic presidential debate in Las Vegas, Oct. 13, 2015. The two hold another debate Sunday in Flint, Mich.

Trump, meanwhile, continues to amass delegates while thumbing his nose at the Republican establishment and straying from traditional presidential themes.

“Look at those hands. Are they small hands?” Trump said at the Fox debate, responding to a jab days earlier from Rubio suggesting that the front-runner has small appendages.

On Tuesday, Michigan and Mississippi are holding both Republican and Democratic presidential primary elections, while Republicans are holding a primary in Idaho and caucuses in Hawaii.